﻿PROCEEDINGS OF THE UNITED STATES NATIONAL MUSEUM 



Issued 



SMITHSONIAN INSTITUTION 

 U. S. NATIONAL MUSEUM 



Vol. 102 Washington: 1952 No. 3302 



ECHINODERMS FROM THE MARSHALL ISLANDS 



By Austin H. Clark 



The echinoderms from the Marshall Islands recorded in this re- 

 port were collected during Operation Crossroads by the Oceano- 

 graphic Section of Joint Task Force One under the direction of 

 Commander Roger Revelle in 1946, and by the Bikini Scientific Re- 

 survey under the direction of Capt. Christian L. Engleman in 1947. 

 The number of species of echinoderms, exclusive of holothurians, in 

 these two collections is 80, represented by 2,674 specimens. Although 

 many of these have not previously been recorded from these islands, 

 a number known from the group were not found, while others that 

 certainly occur there still remain undiscovered. 



Of the 80 species collected, 22 were found only in 1946 and 24 only 

 in 1947; only 34, about 40 percent, were found in both years. It is 

 therefore impossible to appraise the effects, if any, of the explosion 

 of the atomic bombs. But the specimens of the 54 species collected in 

 1947 are all quite normal. On the basis of the scanty and inadequate 

 data available it would seem that the bombs had no appreciable effect 

 on the echinoderms. 



Some of the species are represented by young individuals only. 

 This is always the case in any survey of the echinoderm fauna of any 

 tropical region. A few localities are found to yield nothing but 

 young individuals of certain species at a given time, or possibly unless 

 collections are made over a series of years. 



A few^ of the records are from depths greater than any heretofore 

 recorded for the species. These records are based mostly on dead 

 material, which may have washed down from the shallower water of 

 the reefs, though there is no reason to believe that the animals could 

 not have lived at the depths given. 



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